At a light-hearted dinner party, you might find a scene where a usually shy friend becomes unusually brave after a few drinks, loudly telling secrets that he would not normally dare to confide; Another partner, who is usually talkative, is drowsy and isolated in the corner. These observations raise an interesting question: Why does the same alcohol elicit such different reactions in different people? 
Alcohol, as a widely consumed social medium, has an impact on the human body that goes far beyond momentary excitement and relaxation. When alcohol enters the human body, it is quickly absorbed by the digestive system and enters the brain with the bloodstream to begin its complex physiological effects. Alcohol and the Brain: A Subtle Chemical Dance First, alcohol directly affects the brain's neurotransmission system, specifically the activity of the inhibitory neurotransmitter aminobutyric acid (GABA). GABA plays a role in slowing down nerve activity in the brain. When alcohol enhances the effects of GABA, the brain's inhibitory signals increase, leading to a decrease in the person's self-control and alertness. Courage**: It's not just a feeling that alcohol reduces the brain's response to inhibitory signals, making people feel "bolder". It's not just a psychological effect, it's that alcohol changes the way the brain processes risk and fear messages. It is this physiological change that makes it easier for people to make decisions or behaviors that they would not normally consider under the influence of alcohol. Alcohol and the reward system: Adventurous chemical-based alcohol also activates the reward system in the brain, specifically the pathways associated with dopamine. Dopamine is a neurotransmitter that is closely associated with pleasure, reward, and motivation. When alcohol increases the release of dopamine, the person feels happy and satisfied, increasing the likelihood of engaging in risky behaviors. 
This direct impact on the physiological mechanisms of the brain explains why alcohol can cause people to behave very differently in social situations. From a chemical perspective, alcohol is more than just a social lubricant, it actually reconfigures our neural networks, changing the way we react and process our surroundings. By understanding how alcohol affects the brain and behavior, we can approach drinking more responsibly, recognizing that it is not just a simple way to relax, but a powerful chemical that has the potential to profoundly change our mental and physical state. It's no accident that you become talkative after drinking. Alcohol acts directly on our brains, especially those responsible for social inhibition and anxiety. When alcohol enters the bloodstream, it reduces the activity of inhibitory neurotransmitters in the brain, such as aminobutyric acid (GABA), which normally help us stay calm and self-controlled. As inhibition decreases, our social defense mechanisms decline, leading to more freedom to express thoughts and feelings. In addition, alcohol can also increase the release of dopamine, a neurotransmitter associated with feelings of pleasure and reward. This increased dopamine level makes people feel more fulfilled and enjoyable in social interactions, which encourages more communication and sharing. However, this effect of alcohol is not the same for everyone. Individual differences, such as genetic background, drinking habits, and individual constitutions, can affect the social activation effect of alcohol. The mechanism by which alcohol causes lethargy is also rooted in its direct effects on the brain. Alcohol slows down brain activity, especially in the cerebral cortex, which is the area responsible for thinking and consciousness. As brain activity slows down, the body enters a state of relaxation, which promotes the occurrence of sleep. However, alcohol-induced sleep is not the same as natural sleep. While it may be possible to accelerate the onset of sleep initially, alcohol can actually disrupt sleep quality, especially during deep sleep and rapid eye movement (REM) sleep stages. This explains why sleep after drinking alcohol often doesn't feel completely rested. It is important to note that the drowsy effect of alcohol is closely related to the amount of alcohol consumed. Light to moderate alcohol consumption may promote sleeping, while excessive alcohol consumption may lead to sleep disruption and discomfort the next day. 
By understanding how alcohol affects our social behaviour and sleep patterns, we can approach the relationship between drinking and health more intelligently, ensuring that the pleasure of socializing doesn't come at the expense of physical and mental health.